In a known rectifier of the general type referred to above, for example as described in the German Pat. No. 1 279 850, the tap electrode is composed of two parts between which are placed disc springs which press the semiconductor diodes against the lead conductors. The known device is not protected against atmospheric influences. Furthermore, the lead conductors are collective buses which include at least one further pair of electrodes, making this device impractical when only one pair of diodes is required.